Field of the Disclosure
The disclosure relates to a display panel and in particular to a liquid crystal display (LCD) panel.
Description of Related Art
In 1888 A.D., Friedrich Reinitzer placed a cholesteric benzoate in a polarizing microscope and observed that the cholesteric benzoate appears in different colors (blue-violet and blue) as in an isotropic phase and in a cholesteric phase, and a color variation phenomenon between the isotropic phase and the cholesteric phase merely exists within a rather small temperature range (about a temperature range of 1° C.). In 1970 A.D., a number of scientists confirmed the above-mentioned phenomenon is a new thermodynamically stable phase through conducting volumetric analysis, using high resolution differential scanning calorimetry, and so forth. Said phenomenon is referred to as blue phase (BP).
Normal liquid crystal (LC) is optically anisotropic; by contrast, the BP LC is optically isotropic. In other words, the BP LC has a very low birefringence or does not even have a birefringence. Since the periodic lattice of the BP is a function of a visible light wavelength, a selective bragg reflection may occur. This feature enables the BP LC to be applied to the use of fast light modulators. However, no matter in terms of a theoretical prediction or an experimental observation, the BP LC merely appears in molecular materials possessing high purity and high chirality, thus causing the BP LC to merely exist within a very small temperature range. This is the reason why the BP LC is often discussed in an academic field, whereas the practical application of the BP LC is rather difficult.
In the last decade, in order to enable the display quality of the LCD panel to override the display quality of the cathode ray tube display, the BP LC featuring a rapid response speed again receives the attention from the academia and the industry. To meet application demands, the BP LC is required to possess a wide temperature application range, and therefore different techniques have been proposed. For instance, a feature of stability of polymer (i.e., formation of a reticular polymer structure) is utilized to generate the BP that can exist within a wide range of temperature (see Nature materials, 2002, 1, 64). In addition, in 2002 A.D., Kikuchi et al. successfully produced the BP LC characterized by a temperature range of approximately 60° C. and a stable, gel-like structure. Although the BP LC has the advantages of short response time and optical isotropy, it has the disadvantage of the relatively high driving voltage, which can reach up to 55 volts. From the viewpoint of mass production, the high driving voltage of the BP LC is one of the problems which demands solutions.